Comparison of Fin Tests

If one is to believe fin advertisements, a range of improvements, from modified Venturi openings to split blades, provides such advantages that one ought to be able to power through a five-knot current without breathing hard. As we pointed out as far back as 1991, typically the larger the fins, the more thrust they offer, while the many “innovations” made are largely to differentiate models in advertising. Nonetheless, there can be differences, so Undercurrent has compiled some recent comparative studies of fin performance. Although experts don’t always agree on which fins are best, some do stand out.

Britain’s DIVE magazine recently tested several models to compare the thrust they produced versus the effort required. Longdistance cyclist and diver Steve Moss, who is accustomed to maintaining a constant effort for prolonged periods, tested the fins. He attached a bungee cord to his waist, with the other end attached to a calibrated scale. Other testers concentrated on the fins’ maneuverability, fit, comfort, buckles and straps. They also tried alternative kick styles and surface swimming.

In the end, DIVE’s chief equipment tester, Charles Hood, noted that all the fins were acceptable but differed in durability, maneuverability and power. He recommended that buyers “base your choice on the type of diving that you are doing and on those fin qualities that suit that particular diving.”

Imprex the Top Performer

The top performer was the TUSA Imprex Tri-Ex with a modified solid blade, rated 9.5 out of a possible 10. The magazine reported, “It produced a huge force when power was required.” All test team members also found the Imprex “by far the most comfortable fin tested,” primarily due to the soft material employed in the generous foot pocket. Being lightweight, the fins proved highly maneuverable: “certainly as good as the leading split fins, and great for snorkeling.” Midpriced at $89, they represent “pretty good value for money,” according to the testers.

And while there are those who love to hate the Force Fin, the Extra Force Fin with its distinctive swallowtail blade compared favorably. Though the heel strap broke near the end of the test, DIVE reported, “The thrust is remarkable, and they are a delight while frog kicking. They represent the ultimate in fin technology.” However, Undercurrent wonders who would pay the absurd list price of $495.

Apollo’s Bio-Fin Pro, the prototypical split fin design, was also highly rated for comfort and maneuverability, but less so for thrust. “If agility rather than brute force is your criterion, you should definitely consider these fins,” DIVE observed. Of other split fins tested, the IST Talaria was easy to fit, easy to walk in and highly maneuverable underwater. “As for performance, they are everything you would want,” the testers agreed. The full-foot Scuba Pro Twin Speeds, while positively buoyant, were heavy but felt “robust and well made,” said Hood, adding, “If you dive in a tough environment, these fins are definitely worth considering.” The Aeris Velocity Duo was deemed a “good all-round midrange split fin” but lost out to the Twin Speeds because they produced less thrust.

Quattros Lag the Leaders

The Mares Avanti Quattro came in just behind five other fins. The editors said the Quattros were comfortable and powerful and “made us feel agile while maintaining good control.” The Atomic Split fin, also based on the Nature’s Wing design, was described as “heavy and disappointing in terms of thrust,” earning a rating of just 7 out of 10. Said DIVE, “There are better split fins out there, which are better value for money.” Also rated 7 out of 10 were the Seemann Xdrive Pro, Deep Outdoors Six-Gill, Beuchat X-Jet and Typhoon Tornado.

Another British publication, Diver, tested Apollo, Atomic and Quattro three years ago (reported in the August 2003 Undercurrent). Diver technical editor John Bantin reported that the Apollos and Atomics performed identically on the speedometer in ocean tests over a short course. One tester noted that he could start finning at high speed right away with the split fins. “With the Quattros,” he reported, “I felt as if I was starting in a higher gear, with more pressure on my calf muscle.” Bantin favored the lighter weight Atomics over the Apollos. The Quattros lost because of their extra size in the water, in the boat and in the bag.

DIVE gave the retro-looking black rubber vented IDI Power Fin the same rating as the Quattro (8 out of 10). At a retail price of $75, “these fins give incredible value for money,” said DIVE, adding, “You might be forgiven for thinking these are split fins, as they perform in a similar fashion, due to the soft inner section of the blade, which allows the two outer sides to move independently of one another.”

It’s All in the Kick

With the single-bladed Imprex, Quattro and Power Fin performing competitively with top-of-the-line split-fin models, we want to point to a study reported in the January 2004 Undercurrent that determined that no single design (split or single blade) was inherently better than the other.

More important than any single design feature was the correlation between fin stiffness and hip angle, reflecting a deeper kick and resulting in greater distance of travel per kick. Researchers from State University of New York at Buffalo also determined that the neither the blade material nor the use of flanges, longitudinal splits, vents or ribs increased the velocity of water down the fin and, in fact, may decrease it, thus lowering thrust and economy.

The Buffalo researchers also pointed out that women have significantly lower muscular force than men, so the best fin may be different for women. As we reported in February 2004, for women the most economical fins (i.e., lower energy required when kicking) were the Apollos (either split or taped to make them single-bladed) and the rigid Attack fin (now discontinued and replaced by the Sporasub Instinct full-foot freediving fin), with all others performing similarly to each other. The taped Apollo fin (solid blade) was much better at faster speeds (24 percent higher than the Attack).

Which Is the Fastest?

Professor Jim Grier, a tester for ScubaLab, has found that air consumption efficiency and static thrust highly correlate to average maximum speed. Grier performed open-water speed tests as the criterion for ratings. As a baseline, he selected his own Apollo blue fins, with which he could average 3.25 mph. Grier found that he was able to exceed his Apollo’s average speed with the Aqua Lung Caravelle, Oceanic Caribe, Oceanic V6, Scuba Pro Twin Speed, TUSA FF-9 and Mares Volo-Race.

ScubaLab’sTM Testers’TM Choices

More recently, ScubaLab’sTM fin testers awarded their 2005 Testers’ TM Choice designation to the Apollo Sports Bio-Fin Pro Yellow/C-Series, the Deep Outdoors Six-Gill and the Aeris Velocity Duo (all also rated highly by the editors of DIVE), plus the Mor-Fin Blue Vt-300b among open-heel fins. Among full-foot fins, Testers’TM Choice ratings were bestowed on Atomic Aquatics Splitfin and the Akona Azione.

And the Consensus Is . . .

Those singled out more than once for excellent performance included various models of the Apollo Bio-Fin, Scuba Pro’s Twin Speed, Atomic Aquatics’ Splitfin, and the single-bladed Mares Quattro.

If there seem to be some inconsistencies in the results of these studies, remember that researchers tested different models and brands, at different times, using different technologies. But it’s also because in the end, fins must be judged personally. All the vents, splits, flanges and stats aside, it’s how they feel on your feet and how well they serve the purpose of your diving.